content/renderer/media/audio_device_factory.h

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CONTENT_RENDERER_MEDIA_AUDIO_DEVICE_FACTORY_H_
   6 #define CONTENT_RENDERER_MEDIA_AUDIO_DEVICE_FACTORY_H_
   7
   8 #include <string>
   9
  10 #include "base/basictypes.h"
  11 #include "base/callback.h"
  12 #include "base/memory/ref_counted.h"
  13 #include "content/common/content_export.h"
  14
  15 namespace media {
  16 class AudioInputDevice;
  17 class AudioOutputDevice;
  18 }
  19
  20 namespace url {
  21 class Origin;
  22 }
  23
  24 namespace content {
  25
  26 // A factory for creating AudioOutputDevices and AudioInputDevices.  There is a
  27 // global factory function that can be installed for the purposes of testing to
  28 // provide specialized implementations.
  29 class CONTENT_EXPORT AudioDeviceFactory {
  30  public:
  31   // Creates an AudioOutputDevice.
  32   // |render_frame_id| refers to the RenderFrame containing the entity
  33   // producing the audio. If |session_id| is nonzero, it is used by the browser
  34   // to select the correct input device ID and its associated output device, if
  35   // it exists. If |session_id| is zero, |device_id| and |security_origin|
  36   // identify the output device to use.
  37   // If |session_id| is zero and |device_id| and |security_origin| are empty,
  38   // the default output device will be selected.
  39   static scoped_refptr<media::AudioOutputDevice> NewOutputDevice(
  40       int render_frame_id,
  41       int session_id,
  42       const std::string& device_id,
  43       const url::Origin& security_origin);
  44
  45   // Creates an AudioInputDevice using the currently registered factory.
  46   // |render_frame_id| refers to the RenderFrame containing the entity
  47   // consuming the audio.
  48   static scoped_refptr<media::AudioInputDevice> NewInputDevice(
  49       int render_frame_id);
  50
  51  protected:
  52   AudioDeviceFactory();
  53   virtual ~AudioDeviceFactory();
  54
  55   // You can derive from this class and specify an implementation for these
  56   // functions to provide alternate audio device implementations.
  57   // If the return value of either of these function is NULL, we fall back
  58   // on the default implementation.
  59   virtual media::AudioOutputDevice* CreateOutputDevice(
  60       int render_frame_id,
  61       int sesssion_id,
  62       const std::string& device_id,
  63       const url::Origin& security_origin) = 0;
  64   virtual media::AudioInputDevice* CreateInputDevice(int render_frame_id) = 0;
  65
  66  private:
  67   // The current globally registered factory. This is NULL when we should
  68   // create the default AudioRendererSinks.
  69   static AudioDeviceFactory* factory_;
  70
  71   DISALLOW_COPY_AND_ASSIGN(AudioDeviceFactory);
  72 };
  73
  74 }  // namespace content
  75
  76 #endif  // CONTENT_RENDERER_MEDIA_AUDIO_DEVICE_FACTORY_H_